The present invention relates to a vehicle transmission featuring a large number of gears, particularly for an agricultural tractor or similar. Known vehicle transmissions of the aforementioned type are usually characterised by enabling gear shifting under load, with no interruption in the torque transmitted between the engine and wheels. This is usually achieved by employing selectively engageable clutch means for each gear, or a pair of clutches for two drive shafts connected to respective sets of gears, and further clutch means for connecting said gears to an output shaft.
In both cases, the clutch means are usually operated hydraulically, and controlled via an electronic control system providing for appropriate operating cycles. A major drawback of known transmissions of the aforementioned type is that said operating cycles are determined as a function of average vehicle service conditions, with no regard to other than average load, speed or service conditions. Moreover, the transmission hydraulic circuits and actuators are relatively complex and expensive to produce.